I've got a bath plumbed out of a slab in my basement. It is stubbed with 1.5" drain pipe. There was a clawfoot shower/tub combo in place when I bought the house. I want to put a shower stall in place of the shower/tub. I know min. drain diameter is 2" for shower and 1.5" for combo's or single tubs. My question is since the old system drained just fine can I use the old drain stub and use a 2" to 1.5" reducer to mate the new shower drain with the old stub? My only other option is to break up the slab and find where the 2" pipe is located. That is out of my spectrum and will require a plumber for sure. Would a licensed plumber be allowed to run my new shower drain to the old stub so that I don't have to break up the slab?
Much obliged...
